ch. 15.1-4, 16.1-3 SAC

Question 1

protein

Answer 1

organic polymers made from monomers called amino acids

Question 2

essential amino acids

Answer 2

9 amino acids that cannot be synthesised by the body so must be obtained in the diet

Question 3

complementary proteins

Answer 3

combination of proteins that is able to provide the complete set of all the essential amino acids for the diet

Question 4

structure of amino acids

Answer 4

amino, carboxyl, hydrogen, r group

Question 5

r group

Answer 5

differentiates amino acids

Question 6

zwitterion

Answer 6

dipolar ion formed when the amino and carboxyl groups in an amino acid or polypeptide are both charged but the overall ion is neutral

Question 7

dipeptide

Answer 7

organic molecule that has bee produced by the condensation reaction between two amino acids

Question 8

formation of a dipeptide

Answer 8

2 amino acids = dipeptide and water

Question 9

peptide / amide linkage

Answer 9

CONH

Question 10

tripeptide

Answer 10

an organic molecule made from three amino acid units linked by peptide bonds

Question 11

condensation reaction

Answer 11

reaction in which two molecules link together by eliminating water molecule

Question 12

polypeptide

Answer 12

organic polymer molecule made from a condensation reaction between amino acids

Question 13

a polypeptide made from how many amino acids is a protein

Answer 13

more than 50

Question 14

N terminal

Answer 14

end of the chain with a free amino group (NH2)

Question 15

C terminal

Answer 15

end of the term with a free carboxyl group (COOH)

Question 16

primary structure

Answer 16

the sequence (number, order and type) of amino acids in a polypeptide chain

Question 17

secondary structure

Answer 17

initial level of spatial arrangement of a polypeptide chain. a-helices and b-pleated sheets

Question 18

how is secondary structure formed

Answer 18

hydrogen bonding between polar -NH group in one peptide link and the polar -C=O in another peptide link at regular intervals along the same chain

Question 19

tertiary structure

Answer 19

overall three dimensional shape of a polypeptide chain formed by the folding and twisting of the protein

Question 20

forms of tertiary structure

Answer 20

flat sheets.
long helixes.
compact globular shapes

Question 21

bond types in tertiary structures

Answer 21

hydrogen bonds.
dipole-dipole interactions.
ionic interactions.
covalent cross-links.
dispersion forces

Question 22

quaternary structure

Answer 22

highest level of organisation in protein structure.

composed of 2 or more polypeptides

Question 23

forces that hold polypeptide chains together

Answer 23

mainly dispersion forces

Question 24

nutrients

Answer 24

large biomolecules that are used to provide nourishment for growth or metabolism

Question 25

metabolism

Answer 25

all the chemical processes occurring within a living cell or organism that are necessary for the maintenance.
breakdown of food.
synthesis of molecules.

Question 26

digestion

Answer 26

the breakdown of large insoluble molecules into smaller, soluble molecules

Question 27

process of digestion

Answer 27

mouth -> stomach -> small intestine -> large intestine

Question 28

digestion of carbohydrates

Answer 28

mouth (amylase) -> small intestine (duodenum, jejunum) with digestive enzymes from pancreas

Question 29

digestion of proteins

Answer 29

pepsin (stomach) -> shorter polypeptides move into duodenum ->dipeptides -> amino acids

Question 30

digestion of triglycerides

Answer 30

lipase (duodenum) -> produces glycerin and fatty acids

Question 31

hydrolysis

Answer 31

involve splitting large molecules by their reaction with water molecules

Question 32

condensation

Answer 32

involve joining two smaller molecules to form larger molecule with the elimination of a water molecule

Question 33

enzyme

Answer 33

protein molecule that functions by catalysing a specific biochemical reaction by lowering activation energy.
biological catalyst

Question 34

biological catalyst

Answer 34

proteins called enzymes that increase the rate of reaction by 10^10

Question 35

active site

Answer 35

site at which a reaction is catalysed. hollow or cavity in protein structure where enzyme bonds with substrate

Question 36

substrate

Answer 36

reactant in a reaction that is catalysed by an enzyme at the active site

Question 37

lock and key model

Answer 37

substrate fits perfectly into the active site.

highly specific

Question 38

induced fit model

Answer 38

active site changes shape slightly to fit the substrate

Question 39

are amino acids chiral

Answer 39

yes.

exist as optical isomers enantiomers

Question 40

coenzyme

Answer 40

an organic molecule that is required by an enzyme in order to catalyse a reaction

Question 41

cofactor

Answer 41

metal ion or small molecule that combines with an enzyme and is required for enzyme activity

Question 42

enzyme activity

Answer 42

the amount of substrate that is converted to products per unit time

Question 43

optimum pH

Answer 43

pH at which the enzyme activity is at its greatest

Question 44

optimum temperature

Answer 44

temperature at which the enzyme activity is the greatest

Question 45

temperature increases above optimum temp

Answer 45

increased kinetic, disrupt structure, increased movement breaks intermolecular forces responsible for tertiary and quaternary, change in 3D means active site changes, decreased reaction rate

Question 46

temperature decreases below optimum temp

Answer 46

lower kinetic energies, less frequent and less energetic collisions

Question 47

denatured

Answer 47

change in 3D shape so its unable to function as a catalyst

Question 48

increased temp and pH

Answer 48

alter enzyme structure by breaking hydrogen bonds, substrate doesn’t fit active site, enzyme loses activity, denatured